The Russian Federation was at 4th as it managed to edge Canada--previously at No. 3--out of the top 5 ranking. Opera Mediaworks highlighted the Russian Federation as one of the most noticeable growth markets in the quarter.

The report said ad impressions in the Russian Federation increased over 60 percent from the end of the third quarter to the fourth quarter. The growth trajectory in ad impressions in the Russian Federation parallels the increased adoption of Android devices which rose over 22 percent, it added.

India remained 5th. The remaining Asia-Pacific markets in the top 20 were Japan at 10th, Vietnam at 11th, Australia at 14th and Malaysia at 20th. Malaysia was previously at 21st position in the third quarter.

Market share of APAC ad impression stagnantIn the second quarter of 2012, eight Asia-Pacific countries were in the ranking. The number dropped to seven in the third quarter while the fourth quarter only had six.

The decrease of Asia-Pacific markets in the top 20 ranking could be explained by the stagnant ad requests and impression volume in the region. Asia-Pacific had 14.4 percent market share in ad requests and impression volume in the fourth quarter, a miniscule increase from 14 percent in the third quarter.

North America was the only region which had a drop in the market share of ad request. In the fourth quarter, it had 63.96 percent market share, down from 70 percent in prior quarter.

The market share of ad impressions for the rest of the regions were growing. Market share for European Union grew to 14.61 percent, up from 10 percent in the third quarter.

Market share for ad impressions in Africa increased to 3.39 percent from 2 percent. Middle East saw a small growth to 2.2 percent, from 2 percent in the previous quarter. Central and Latin America share grew to 1.45 percent from 1.3 percent.